All things related to multicast

[Michael Lambert <>]

I have two hosts on the same subnet running beacon 1.3.  One is an  
x86 MacBook Pro running Mac OS X 10.4.9.  It hears and is heard by O 
(all) other beacons.  The other is an Alpha running FreeBSD 6.2.  It  
hears everyone, but nobody (even the other beacon on the same subnet)  
hears it.

The switch ports (adjacent in the switch) for the two hosts are  
configured identically.

An excerpt of 'show ip mroute summ' on the first-hop router shows:

  (xxx.xxx.xxx.60, 233.4.200.18), 00:29:44/00:03:25, OIF count: 1,  
flags: TA
  (xxx.xxx.xxx.159, 233.4.200.18), 00:27:53/00:03:25, OIF count: 1,  
flags: TA

On the second hop it's:

  (xxx.xxx.xxx.60, 233.4.200.18), 00:29:17/00:03:25, OIF count: 2,  
flags: T
  (xxx.xxx.xxx.159, 233.4.200.18), 00:27:27/00:03:25, OIF count: 2,  
flags: MT

If I ping 224.0.0.1 from the Mac (.159), it's own address shows up in  
the returns, but the Alpha's doesn't.  If I ping 224.0.0.1 from the  
Alpha (.60), it's own address does NOT show up, but the Mac's does.

I'm suspecting some sort of kernel/system configuration issue on the  
Alpha, but I'm not sure where to look.  I'd appreciate any suggestions.

Thanks,

Michael